Isuzu Trooper Owners Club UK™

[marvo]

yes i've had a really bad time with the box dropping out of overdrive and dropping a cog as well, the result being a teeth chattering redline, brown pants experience! as it always seemed to happen when overtaking on the local motorway!
i read this forum but figured it was'nt the speed sensor, no wild swinging about,checked my at fluid level when warmed up,that was fine,then a check engine would come on now and then as well as the downshifting, tried everywhere for diagnostics around the Plymouth area,no one could read an import! sounds familiar anyone?
Decided to try a local transmission specialist who also sells the launch diagnostic systems to local garages in the area,they could read the codes (tech 2) but none were present, so started to check the various sensors which feed the transmission computer and hey presto, i was the proud owner of a faulty temperature sensor,I think it is positioned vertically into the top of the thermostat housing, and now i am driving a different car that does not scream at 4000 rpm at 70 mph, wonderful, cost of a new sensor approx £30, my eternal thanks must go to D.J. TRANSMISSIONS, HUXLEY CLOSE, PLYMOUTH. they deserve a plug for the great job when no one else could help me. hope this has helped a few more of you out there, with the same problem. all the best Marvo

[Google]

[davedgreat]

Well done Marvo, this is what this forums about.
Regards Dave

[marvo]

a couple of weeks on and still going great. just to clarify,when the original problem with the downshifting was noticed,there was no warning light for about three months,just downshifting without warning. it was only after this time that the check engine light started to come on occasionally as the problem started to get worse and happen more often.

[matt1275]

Dont suppose you could verify which sensor it is could you I have the same problem exactly and no one near to me has the gear to read codes or even seem to have the enthusiasm to check the thing properly,I feel like driving the 350 miles to plymouth to see these guys but at 70 mph going slowly deaf its not as attractive a proposition as whacking the truck with a bush
Cheers Matt
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1990 2.8 Lotus Trooper is this rare?

[marvo]

hi matt,
i have a 3.1 deisel 95 bighorn,so the info i give you is for my car and hopefully it will be similar or the same for yours too.if you trace the top hose back from the radiator to the thermostat housing,you should find two sensors that screw down into the top of the thermostat housing(they will have some wires going to them) on my car the sensor closest to the front and left of the car(standing in front) was the faulty one,and was replaced.
these are just switches,that prevent the transmission being over stressed before the engine warms through, i think you could unplug the cable that connects to the sensor and short out the pins of the plug when the engine is warm! but dont quote me on that,its just what the guy who fixed mine told me that he did,for a quick check,before replacement.
if you have problems sourcing a replacement let me know and i can give you the phone number of the dealer where my sensor was bought from.
hope this helps and let me kow if you need any more info,all the best.marvo

[matt1275]

Cheers mine does exactly as yours i tried shorting all at different times but no difference so i'll replace that one and see what happens
cheers matt
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1990 2.8 Lotus Trooper is this rare?

[marvo]

hope you get there in the end,as a last resort try a local transmission specialist in your area, i ran around so many garages,even so called isuzu dealers and they were all useless. trouble is there are too many sensors on cars nowadays,good luck and let me know how you get on.

[marvo]

its just struck me,that if you have tried shorting the wires out,perhaps a wire is broken or damaged from a sensor,if shorting makes no difference,it could be a loose or brokenwire and not the sensor.

[IanP]

Hi, tried linking out that sensor, and found after a bit of cursing in the frost, that its the glow plug sensor (plugs went out after 1 second at -1C). I thought that the gearbox oil temp had its own sensor to prevent overloads with cold oil. Can you confirm it was the sensor at the front of the thermostat housing on the drivers side that was at fault?
Cheers

[marvo]

hi ,you have me wondering whether i am sane now!, i will check tomorrow and get back to you,although one of the problems i had at the same time as the trans prob was also short one second glow plug times. there are of course many sensors feeding info back to the transmission computer but i cant imagine the garage would change more than one and not charge me for it, regards marvo

[eithan h]

im pretty certain that the equipment isuzu dealers use won't read imports so i wouldn't be surprised they didn't want to know

[ealderton]

I THINK WE MAY HAVE THE SAME PROBLEM. HAVE JUST POSTED THE BELOW ON THE FORUM, BUT I AM REALLY WONDERING ABOUT THE NEW THERMOSTAT!

DO YOU HAVE THE PHONE NUMBER FOR D.J. TRANSMISSION?

THANKS!

Hello,



I just joined.



We have an Isuzu Trooper 3.1 Automatic, and live in Ireland. The vehicle is a Japanese import, so is the ‘new shape’ and is dated 1994



Background



Up to the following events the vehicle has been perfect. Smooth running and is in perfect condition .



About 4 years ago we had the speedometer break down. This caused the side-effect of the gearbox not changing to 4th. The speedometer was replaced and the gearbox immediately went back to normal.



Friday 14th January



Trooper in for service and to have timing belt changed (has done almost 200,000 miles, 300,00 km)



Whilst there the garage drained and refilled the automatic transmission fluid (don’t know why)



They also had to reset the light on the dashboard that warned of the timing belt change need



They also replaced the thermostat. Engine now running much warmer, gauge at half way. Heater now efficient.



Saturday 15th January



Long trip – about 100 miles each way. After about an hours driving, the vehicle kept dropping back to 3rd from 4th gear, then stopped going into 4th at all



We carried on, more slowly



On the return trip it was absolutely fine. Going into 4th and as smooth as silk



Sunday



Short trips. Fine



Monday



Back to garage, who tightened the jubilee clips



Tuesday



Short trips. Fine



Wednesday



Long trip – about 100 miles. After half an hour’s driving the vehicle stopped going into 4th gear.



On return trip after half an hour it stopped going into 4th gear



Has not gone into 4th gear since.



Thursday



Back to garage. They confessed that they had not put enough fluid into the transmission. 3 litres instead of 8







Question



Is the above lack of fluid the cause of damage to the gearbox?



Does anyone think this could be electrical?





Many thanks



E. Alderton

[davedgreat]

JUST TRY LINKING OUT THE PLUG THAT CONNECTS TO THE TEMP' SWITCH MENTIONED ABOVE, WHEN THE FAULT OCCURS, THIS WILL PROVE THE SWITCH, AS MENTIONED ABOVE. READ THE ABOVE
PLEASE READ THE ABOVE!
As it sounds like a intermittant fault, Which are usually electrical.

[T J Mannix]

Hi, I have had major difficulty in getting help for this problem, I wish that i had seen your posting sooner. Can you let me know how to get the sensor PLEASE. I tow all over the UK and my wife is tired of my tirades when we hit 3400 RPM, her fix is to tap the dash sharply and say "OH DO BEHAVE", all this being said we both love our Bighorn, thanks for your time, I am a newbie.

[ealderton]

Probably worth trying POWER DRIVE if you have that option. Our Isuzu (3.1 1994) behaves quite differently in POWER DRIVE and doesn't hunt the gearbox so much.